Liquid spraying apparatus



Feb. 15, 1966 G. B. BoYcE LIQUID SPRAYING APPARATUS 2 Sheets-Sheet 1 Filed Jan. 10, 1964 United States Patent liice 3,235,186 Patented Feb. is, ieee 3,235,136 LIQUlB SPRAYNG APPARATUS Guy Baron Boyce, Shenstnne, England, assigner, `by mesne assignments, to Elinks-Ballons Limited, Erownhills, Sta'ordshire, England, a company of England Filed Ilan. 10, 1964, Ser. No. 336,998 Claims priority, application Great Britain, Nov. 20, 1963, 45,766/63 9 Claims. (Cl. 239--415) This invention relates to liquid spraying apparatus of the kind comprising a housing, a liquid inlet, an air inlet, a passage in the housing connecting said liquid inlet to a liquid nozzle, liquid valve means for controlling the flow of liquid through said passage, further passages connecting said air inlet to a primary air nozzle adjacent the liquid nozzle and to a secondary air nozzle which is spaced from the liquid nozzle and which is, in use, adapted to direct a jet of air towards the stream of tinely divided liquid issuing from the Aliquid nozzle for the purpose of forming said stream to a tlattened configuration and air valve means for controlling the flow of air through said further passages.

It is an object of the invention to `provide liquid spraying apparatus of the kind specified in a convenient form.

In accordance with the invention the liquid valve means and the air valve means are provided with a common operating member and the arrangement is such that the operating member can be moved to increase the supply of air to said secondary nozzle without substantial alteration of the supply of air to the primary air nozzle and simultaneously to increase the supply of liquid to the liquid nozzle. j

The invention will now be more particularly described with reference to the accompanying drawings wherein:

FIGURE l shows, in cross-section, one example of liquid spraying apparatus in accordance with the invention;

FlGURES 2, 3, 4 and 5 are fragmentary sections on the lines 2 2, 3 3, 4--4 and 5-5 respectively in FIG- URE l.

in the example shown the apparatus comprises a body 19 having an air inlet 11 and a liquid inlet 12. The liquid inlet 12 leads into a liquid chamber 13 which terminates in a liquid nozzle 14. The iiow of liquid from the nozzle 14 is controlled at the nozzle `by liquid valve means comprising an elongated needle 15 which slides through a gland 16 at the opposite end of the liquid chamber 13. The needle 11S is secured at its opposite end `to an adjusting element 17 which is screw-threadedly connected to an actuating element 18 slidably mounted in a bore 19 in a sleeve 3d forming part of the body. The adjusting element 17 is engaged by a spring 20 which is loaded against an abutment 21 in the bore 19, so that the end or" the needle 15 is urged into sealing engagement with the interior of the liquid nozzle 14. ln this closed position of the needle 15, the distance by which the actuating element 1% projects from the body can be adjusted by engaging a suitable tool with a socket 17a in the adjusting element 17 and turning the latter. Access to the socket 17a is gained by removing a plug 22 in the end of the bore 19.

The nozzle assembly also provides a primary air nozzle 23 which is of annular form surrounding the liquid nozzle 14. As shown the nozzle assembly is in three parts, a rst part 24 of which provides the liquid nozzle 14E- and is screw-threadedly attached to the body proper. The second nozzle part Z comprises a screw-threaded ring by means of which the third nozzle part 26 is attached to the rst part 243, The third part 26 is shaped sealingly to engage the rst part 24 over two frusto-conical areas so as thereby to provide in the nozzle assembly two annular chambers 27 and 28. The chamber 27 communicates with a bore through which the nose of nozzle part 24 projects to form the aforementioned annular primary air nozzle 23. It is known in the art to provide further primary air nozzles in the form ol narrow bores in the part 26 although these are not shown in the drawings. These further primary air nozzles assist in atomizing the liquid stream issuing from the liquid nozzle.

Also formed in the third nozzle part 26 are a pair of oppositely disposed secondary air nozzles 29 formed in wings on the part 26. These nozzles 29 are inclined towards the axis of the liquid nozzle 14 so that, in use, air issuing from nozzles 29 serves to hatten the stream of atomised liquid issuing from the nozzle 14. The secondary air nozzles 29 communicate with the annular chamber 28.

The supply of air to the primary and secondary air nozzles is controlled by air valve means comprising a pair of valves denoted in the drawing by reference numerals 31 and 32. These valves receive their air supply from a common air chamber 33 which is connected by a passage 34 to the air inlet 11. The valve 31 comprises a closure member 35 having a stem 36 projecting through a gland 37 in the body. The closure member 35 is urged by a spring 38, loaded against a cap 39, into engagement with a seat dal so that the air chamber 33 is normally divided oft from a lirst valve chamber 41. Similarly the valve 32 comprises closure member l2 (ofY larger area than closure member 35), stem 43, spring 44, cap 4S, gland 46 and second valve chamber 47, As will be evident from FIGURE 2 the stems 36 and 43 are or" different lengths so that the rst valve stern 36 projects from the body lil further than the second valve stem 43.

Formed in the body il@ are rst and second longitudinal passages 48 and 49 which are connected respectively to the rst and second valve chambers 41, di' by means of cross passages 50, 51. These cross passages 5t?, 51 intersect th-e bore in which the sleeve 3@ is mounted and are sepaarted therein by a flange 39a on the sleeve 3l).

Each of the passages d8, i9 communicates with an annular space 52 formed between the hrst nozzle part 24 and the body lil. The annular space 52 is connected to the annular chamber 28 and thereby to the secondary air nozzles 29 by means of bores 53 in the first nozzle part 24. Also formed in the body is an inclined passage 54 which connects the longitudinal passage 4S 'to another annular space 55 formed between the body 1t) and the first nozzle part The annular space 55 is connected to the annular chamber 27 by further bores Se in the nozzle part 2.4. Each of the passages 48, i9 contains a rod 57, 53 which is longitudinally adjustable to allow its tapered nose to `form a variable air-how restrictor for air flowing to the space 52. The tlow of air through passage 54 is not aiected by adjustment of the rods 57, 58 as the latter co-act with shoulders in the passages dit, t9 downstream of the passage 5d.

The apparatus is completed by a common operating member 52 which is of forked form straddling the body lil and pivotally connected thereto on an axis tl. The needle 1S extends through a hole in the operating member, which is engageable wtih the actuating element 1S and each of the air valve stems 36 and 43. As shown in FGURE 1 the operating member is initially in engagement with the end of stem 36 but is slightly clear of actuating element 18 and well clear of the end of stern 43.

The primary intended use of the apparatus described is as a spray gun for spraying paint and like material. In this case the air inlet 11 is connected, in use, to a supply of compressed air, whilst the liquid irdet 12 is connected to a supply of pressurise-d paint. On actuation of the control member 59 the operator rst feels the effect of the air pressure acting on closure member 35 and spring 38. On moving the control member, therefore, the valve 31 only is opened. Thus air flows into valve chamber 41, and through cross passage Si) to longitudinal passage 48. The air stream from passage ed splits and part of the stream passes through bore 54 to the primary air nozzle 2d whilst a further part (the amount of which is dependent on the adjustment of rod 57) passes to the secondary air nozzle 29.

After a predetermined opening movement (dependent on the position of the adjustment element 17 the control member encounters the actuating element i8. The operator now feels an additional pressure caused by the spring Ztl, and further opening movement of the control member 59 will now cause the needle l5 to be displaced axially. Such displacement can continue until the control meinber 59 engages the end of valve stem 43 where the air pressure on the closure member d2 and the action of the spring 44 are brought to bear on the control member 5d. The stem '43 thus acts as a temporary stop to limit the movement of the control member when the parts of the apparatus are in a first operating configuration. In this configuration a controlled amount of paint (determined by the setting of the needle l5) leaves the paint nozzle 1.4 and is atomized by air from the primary nozzle 23. In this context it will be noted that, in starting the apparatus, air is supplied to the primary nozzle 23 before paint flow is initiated, thereby avoiding the formation of a jet or' paint from the liquid nozzle M. The amount of secondary air flowing in this first configuration can be adjusted by moving the rod 57 between a position in which it seats on the associated shoulder so that the spray is unshaped by secondary air and is therefore conical, to a position in which a restricted amount of secondary air ows to flatten the spray slightly.

When a wide flattened spray is required the operator can displace the control member S9 to a second operating configuration, in which the valve 32 is opened. Additional air now flows to the secondary nozzles 29 through the passage i9 under the control of rod 5S. Simultaneously the needle l5 is displaced further from the liquid nozzle ld so that the amount of paint owing is increased to a maximum.

With careful adjustment of adjusting element 17 and the rods 57, 55 it can be arranged so that the solid angle subtended by the spray at the nozzle increases in proportion to the amount of paint delivered when the apparatus is changed from tirst to second operating configurations. Thus the paint density will remain constant before and after the change over.

het

The spray gun described is ot particular advantage in i tasks such as the spraying of vehicle bodies where there are large areas to be painted, such as roofs and doors, as well as narr w strips, such as window frames. Whilst applying paint to larger areas the operator would use the apparatus in the second operating configuration and when painting narrow strips he would use the iirst configuration. Thus the wastage of paint would be minimised whilst change from one conguration to another can be effected in an extremely simple manner. llt will be realised that, in actual use, the two air-low restrictors and the settingy of the liquid valve need not be altered once a desirable setting has been obtained.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A liquid spraying apparatus comprising a housing having a liquid inlet, an air inlet, a liquid nozzle, a primary air nozzle for producing a liquid-atomising air stream and a secondary air nozzle for producing a spray-shaping air stream, a needle mounted `in the body for longitudinal `movement and spring-loaded into engagement with the interior of the liquid nozzle so as to control the flow of liquid therefrom, la screw threaded adjusting element attached to the needle, an actuating element having a screw thread coacting with that of the adjusting element and projecting from the housing, a first air valve chamber in the housing,

passage means connecting said rst air valve chamber to the primary air nozzle, additional passage means connecting said first air valve chamber to the secondary air nozzle, adjustable flow restrictor means for varying the flow of air through said additional passage means, a second air valve chamber in the housing, further passage means connecting said second air valve chamber to the secondary air nozzle, adjustable flow restrictor means for varying the flow of air through said further passage means, first and second air valve closure members disposed respectively in said first and second air valve charnbers, first and second stems connected respectively Ito said closure members, and projecting from the housing, the first stem projecting further than the second stem, first and second springs urging said closure members to closed positions, and a common operating member pivoted to the housing and engageable on initial displacement with the first stem and the actuating element to displace the needle from the liquid nozzle and open the first air valve closure member and, on further displacement, with the second stem to open the second air valve closure member whilst displacing the needle further from the liquid nozzle.

2. A liquid spraying apparatus comprising a housing having a liquid inlet, an air inlet, a liquid nozzle, a primary air nozzle for producing a liquid-atomizing air stream, and a secondary air nozzle for producing a sprayshaping air stream, liquid valve means in the housing operable to increase and decrease the fiow of liquid from said liquid nozzle, a irst air valve in the housing controlling the flow of air from said primary nozzle, means in the housing for permitting a restricted liow of air from said secondary air nozzle when the first air valve is opened, a second air valve in the housing independently controlling the flow of air from said secondary air nozzle and a common operating lever for said air valves and said liquid valve means, said common operating member being disposable in a first operating position in which said liquid valve means and said first air valve are open and a second operating position in which the second air valve is also open.

3. A liquid spraying apparatus comprising a housing having a liquid inlet, an air inlet, a liquid nozzle, a primary air nozzle for producing a liquid atomizing air stream and a secondary air nozzle for producing a spray shaping air stream, liquid valve means in the housing for controlling the fiow of liquid through said .liquid nozzle, first and second air chambers in the housing, first and second air valves mounted respectively in said chambers and each comprising a spring loaded closure member and a stem projecting from the housing, the stem of said first air valve projecting further than the stem of said second air Valve, a common operating member mounted on the body for operating said liquid valve means and engageable with said rst and second air valve stems, passage means connecting said first air valve chamber to said primary air nozzle, additional passage means connecting said first air valve chamber to the secondary air nozzle, and further passage means connecting said second air valve chamber to said secondary air nozzle.

4. A liquid spraying apparatus as claimed in claim 3 wherein said second air valve closure member is of larger area than said first air valve closure member.

5. A liquid spraying apparatus as claimed in claim 3 wherein said additional passage means is provided with flow restrictor means.

6. A liquid spraying apparatus comprising a housing having a liquid inlet, an air inlet, a liquid nozzle, a primary air nozzle for producing a liquid atomising air stream, and a secondary air nozzle for producing a spray shaping air stream, a longitudinally movable needle mounted in the housing and engageable in the interior with said liquid nozzle to control the flow of liquid therefrom` a first air valve in the housing controlling the flow of air from said primary air nozzle, means permitting a restricted How of air from said secondary air nozzle when the irst air valve is open, a second air valve in the housing independently controlling the ow of air to said secondary air nozzle, and a common operating member operatively connected to said needle and said rst and second air valves and mounted on the housing so as to be movable between a first operating position in which said needle is displaced from the liquid nozzle and said irst air valve is opened, and a second operating position in which said needle is displaced further from said liquid nozzle and both of said rst and second air valves are opened.

7. A liquid spraying apparatus comprising a housing and a liquid inlet, an air inlet, a liquid nozzle, a primary air nozzle for producing a liquid-atomizing air stream, a secondary air nozzle for producing a spray-shaping air stream, a longitudinally movable needle mounted in the housing and engageable with the interior of said liquid nozzle to control the ow of liquid therefrom, first and second air valve chambers in the housing, first and second air valves mounted respectively in said chambers and each comprising a spring loaded closure member and a stem projecting from the housing, the stern of said rst air valve projecting further than the stem of second air valve, a common operating member mounted on the body and adapted to displace the needle from the liquid nozzle by a distance determined by the displacement of the operating member and engage said rst and second air valve stems, passage means in the housing connecting 6 said first air valve chamber to said primary air nozzle, additional passage means connecting said first air valve chamber to said secondary air nozzle, and -further passage means in the housing connecting said second air valve chamber to said secondary air nozzle.

8. A liquid spraying apparatus as claimed in claim 7 wherein said second air valve closure member is of a larger area than said first air valve closure member.

9. A liquid spraying apparatus as claimed in claim 7 wherein said additional passage means is provided' with flow restrictor means.

References Cited by the Examiner UNITED STATES PATENTS 1,627,117 5/ 1927 Preble et al. 239-297 1,779,922 10/1930 Thompson Z39-413 2,626,188 1/1953 Dalrymple 239-415 2,670,239 2/ 1954 Ditch 239-415 2,724,615 11/1955 Ariotti 239-415 2,737,415 3/ 1956 Wheeler et al. 239-290 2,739,843 3/1956 Baur 239-414 2,780,496 2/1957 Asbeck et al 239-415 2,786,716 3/1957 Peeps 239-415 FOREIGN PATENTS 966,200 7/ 1957 Germany.

M. HENSON WOOD, IR., Primary Examiner.

EVERETT W. KIRBY, Examiner. 

2. A LIQUID SPRAYING APPARATUS COMPRISING A HOUSING HAVING A LIQUID INLET, AN AIR INLET, A LIQUID NOZZLE, A PRIMARY AIR NOZZLE FOR PRODUCING A LIQUID-ATOMIZING AIR STREAM, AND A SECONDARY AIR NOZZLE FOR PRODUCING A SPRAYSHAPING AIR STREAM, LIQUID VALVE MEANS IN THE HOUSING OPERABLE TO INCREASE AND DECREASE THE FLOW OF LIQUID FROM SAID LIQUID NOZZLE, A FIRST AIR VALVE IN THE HOUSING CONTROLLING THE FLOW OF AIR FROM SAID PRIMARY NOZZLE, MEANS IN THE HOUSING FOR PERMITTING A RESTRICTED FLOW OF AIR FROM SAID SECONDARY AIR NOZZLE WHEN THE FIRST AIR VALVE IS OPENED, A SECOND AIR VALVE IN THE HOUSING INDEPENDENTLY CONTROLLING THE FLOW OF AIR FROM SAID SECONDARY AIR NOZZLE AND A COMMON OPERATING LEVER FOR SAID AIR VALVES AND SAID LIQUID VALVE MEANS, SAID COMMON OPERATING MEMBER BEING DISPOSABLE IN A FIRST OPERATING POSITION IN WHICH SAID LIQUID VALVE MEANS AND SAID FIRST AIR VALVE ARE OPEN AND A SECOND OPERATING POSITION IN WHICH THE SECOND AIR VALVE IS ALSO OPEN. 